Tea saponin extract, preparation method and application thereof in agricultural synergist

Abstract

The application provides a tea saponin extract, a preparation method and application thereof in agricultural synergists, and belongs to the technical field of biological agricultural adjuvants. The tea saponin extract is prepared from oil tea cake meal as raw material through drying and degreasing, ultrasonic-assisted ethanol extraction, membrane separation and purification, nanofiltration membrane concentration, and finally drying and forming. The tea saponin extract prepared through the specific green integrated process has excellent surface activity and biocompatibility, and is mainly used as an agricultural synergist to improve the wetting, spreading, adhesion and penetration performance of pesticide liquid, and is mixed with multiple components to prepare a synergist through a fermentation preparation process, and can be used as a natural insecticidal and bactericidal component. Compared with single tea saponin or a physical mixture without fermentation, the synergist can significantly improve the wetting, spreading and penetration capacity of the pesticide liquid, is safe to crops, and can improve the synergistic range of multiple pesticides by 30% to 80%.

Description

Technical Field

[0001] This invention relates to the field of biological agricultural adjuvants technology, and in particular to a tea saponin extract, its preparation method, and its application in agricultural synergists. Background Technology

[0002] During pesticide application, the contact angle and adhesion of the pesticide solution on the target plant (especially tropical crops with waxy or hydrophobic leaves, such as bananas, mangoes, and lychees) are too large, resulting in a pesticide loss rate as high as 60%-70% and a utilization rate of only 20%-30%. This not only causes economic losses but also leads to serious non-point source pollution.

[0003] To address this issue, chemically synthesized synergists (such as organosilicon compounds and alkyl ethyl sulfonates) have been widely used. However, these synergists have significant drawbacks: 1) they are not easily degraded in the environment, posing a risk of residue; 2) they can cause phytotoxicity to some crops; and 3) long-term use may affect the soil microbial community.

[0004] Tea saponin, a natural pentacyclic triterpenoid saponin extracted from camellia oil cake, is an ideal substitute for chemically synthesized synergists. It is not only a high-performance natural nonionic surfactant (its surface tension in a 0.1% aqueous solution can be reduced to approximately 40 mN / m), but it also possesses antibacterial and insecticidal biological activities.

[0005] However, existing technologies for directly using crude or refined tea saponin extracts as agricultural synergists have significant limitations: 1. Cost-benefit imbalance: The pursuit of high purity (e.g., >90%) through the use of fine purification processes such as macroporous resins leads to high production costs, making it difficult to promote and apply in agrochemical products with relatively low added value.

[0006] 2. Mismatch between process and demand: As a synergist, the key lies in its surface activity and synergistic effect with other excipients, rather than chemical purity. Over-purification, while removing impurities, may also remove other natural components with synergistic effects (such as certain flavonoids and polysaccharide derivatives that retain activity), and it also consumes a lot of energy.

[0007] 3. Negative impacts of impurities: On the other hand, crude extracts (such as aqueous extracts or simple alcohol extracts) contain high levels of impurities such as starch, protein, and colloids, which can easily lead to poor physical stability of pesticide formulations (such as precipitation, stratification, and foaming), clog nozzles, and may also cause adverse reactions with certain active ingredients of pesticides.

[0008] Therefore, there is an urgent need in this field for a tea saponin extraction and refining process tailored to the application scenarios of agricultural synergists, maximizing the retention and optimization of its surface and biological activities. More importantly, in existing technologies, tea saponin is mostly added directly as a single adjuvant, failing to fully utilize its synergistic potential after being compounded with multiple functional excipients and fermented by microorganisms. This invention addresses this technological gap by providing a novel method for preparing agricultural synergists through fermentation with tea saponin extract as the core and compounded with 10-20 excipients. Summary of the Invention

[0009] In view of this, the purpose of the present invention is to provide a method for preparing tea saponin extract, wherein the tea saponin extract prepared by the method has excellent surface activity and good compatibility with pesticide formulations at a moderate purity (60%-80%).

[0010] The present invention relates to the application of a tea saponin extract, wherein the tea saponin extract is added as an agricultural synergist to a pesticide composition; the pesticide composition includes the active pesticide ingredient and the agricultural synergist; the content of the tea saponin extract in the pesticide composition is 0.1wt%-5wt%; the formulation of the pesticide composition is any one of aqueous solution, emulsifiable concentrate, wettable powder, suspension concentrate or water-dispersible granules.

[0011] Preferably, the agricultural synergist is prepared by fermentation of the following raw materials using microbial strains in weight percentage: Tea saponin extract 30-100%, auxiliary functional materials 0-70% The inoculation amount of the microbial strain is 0.5% to 5% of the total mass of the agricultural synergist.

[0012] Preferably, the preparation method of the agricultural synergist includes the following steps: (1) Mix tea saponin extract with auxiliary functional materials in a certain proportion, add water to adjust the water content to 50-80%, and adjust the pH to 5.5-7.0; (2) Introduce the microbial fermentation strain and mix thoroughly; (3) Ferment at 30-37℃ for 24-72 hours; (4) After fermentation, dry and pulverize or directly prepare into liquid form to obtain the agricultural synergist.

[0013] More preferably, the microbial strain is selected from one or more of Bacillus subtilis, yeast, lactic acid bacteria, and actinomycetes.

[0014] Preferably, the method for preparing the tea saponin extract includes the following steps: (1) Pretreatment and degreasing: The camellia oil cake is dried to a moisture content of <8%, pulverized to 20-40 mesh, extracted with petroleum ether to remove residual oil, and dried to obtain degreased cake powder; (2) Ultrasonic-assisted ethanol extraction: The defatted cake powder is mixed with an ethanol aqueous solution, and after ultrasonic extraction, the supernatant is collected by centrifugation and filtration. The filter residue is extracted once more, and the two supernatants are combined to obtain the camellia cake extract. (3) Membrane separation purification: a. Microfiltration clarification: The camellia seed cake extract obtained in step (2) is filtered using a ceramic microfiltration membrane to obtain a microfiltration clarified liquid; b. Ultrafiltration to remove impurities: The microfiltration clarified liquid is filtered through an ultrafiltration membrane to obtain the ultrafiltration permeate; (4) Nanofiltration membrane concentration: The ultrafiltration permeate is dehydrated and concentrated to 1 / 6-1 / 5 of its volume by passing it through a nanofiltration membrane to obtain a concentrated solution with a tea saponin content of 60%-80%. (5) Drying and shaping: The concentrated liquid is spray dried, with the inlet air temperature controlled at 160-180℃ and the outlet air temperature controlled at 80-90℃ to obtain the tea saponin extract.

[0015] More preferably, the boiling range of the petroleum ether in step (1) is 60-90℃, the extraction is Soxhlet extraction or stirring extraction, the extraction temperature is 50-60℃, and the extraction time is 2-3h; The drying temperature is 50-55℃, and the drying method is ventilation drying, until no petroleum ether solvent residue remains.

[0016] More preferably, the volume fraction of ethanol in the aqueous ethanol solution in step (2) is 60%-75%; the ratio of the defatted cake powder to the aqueous ethanol solution is 1g:8-10mL. The ultrasonic power density is 0.3-0.5 W / mL, the extraction temperature is 50-65℃, and the ultrasonic treatment time is 20-30 min; The centrifugation speed is 4000-5000 rpm, and the time is 10-15 min.

[0017] More preferably, the pressure of the ceramic microfiltration membrane in step (3) is 0.8-1.0 bar, and the pore size of the ceramic microfiltration membrane is 0.1-0.5 μm; The ultrafiltration membrane is filtered at a pressure of 1.5-2.5 bar, and the ultrafiltration membrane is a spiral-wound polysulfone (PS) or polyethersulfone (PES) ultrafiltration membrane with a molecular weight cutoff of 10kDa-30kDa.

[0018] More preferably, the nanofiltration membrane concentration pressure in step (4) is 1.0-2.0 MPa, and the molecular weight cutoff of the nanofiltration membrane is 200-500 Da.

[0019] More preferably, the tea saponin extract contains 60%-80% tea saponin; and the static surface tension of a 0.1 w / v% aqueous solution of the tea saponin extract at 25°C is ≤40 mN / m.

[0020] The remaining components of the tea saponin extract are soluble sugars, small molecule flavonoids and other natural plant ingredients that are allowed to coexist. It is a uniform powder ranging from brownish-yellow to light brown, with no odor or a slightly characteristic odor. The total soluble sugar content is 8%-15%, specifically including glucose 2.5%-4.0%, fructose 1.8%-3.2%, sucrose 2.0%-4.5%, raffinose 0.8%-2.0%, and stachyose 0.9%-1.3%; the total small molecule flavonoid content is 3%-8%, specifically including quercetin glucoside 0.8%-2.0%, kaempferol rutin glycoside 0.6%-1.8%, myricetin 0.5%-1.5%, quercetin 0.4%-1.2%, kaempferol 0.3%-0.8%, and apigenin 0.4%- 0.7%; other natural plant components total 5%-12%, specifically including 1.5%-3.5% phytosterols (β-sitosterol, stigmasterol), 1.2%-3.0% free amino acids (alanine, aspartic acid, glutamic acid), 0.5%-1.0% theophylline, 0.8%-1.5% terpene lactones, and 1.0%-3.0% soluble minerals (potassium, calcium, magnesium), while controlling moisture ≤3.0%, protein residue ≤0.1%, and not containing macromolecular polysaccharides with a molecular weight >20kDa, crude fiber, and lignin.

[0021] The auxiliary functional materials described in this invention are selected from molasses, soybean meal, corn steep liquor, wheat bran, seaweed powder, amino acid powder, humic acid, fulvic acid, chitosan, lignin sulfonate, alkyl glycosides, Tween compounds, polyethylene glycol, urea, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, yeast powder, sodium lactate, glycerol, sodium alginate, glucose, sucrose, starch, fish protein hydrolysate, potassium humate, chitin, soapberry powder, tea seed powder, citric acid, malic acid, tartaric acid, sodium acetate, sodium propionate, sodium butyrate, calcium lactate, zinc sulfate, boric acid, ammonium molybdate, manganese sulfate, copper sulfate, cobalt sulfate, sodium selenite, calcium nitrate, potassium nitrate, ammonium sulfate, dipotassium hydrogen phosphate, potassium chloride, calcium chloride, magnesium chloride, sodium sulfate, calcium carbonate, sodium bicarbonate, potassium silicate, sodium silicate, and bentonite. Kaolin, diatomaceous earth, activated carbon, zeolite powder, talc powder, white carbon black, starch phosphate, sodium carboxymethyl cellulose, xanthan gum, guar gum, gum arabic, gelatin, polyvinyl alcohol, polyacrylamide, polyethylene glycol, polypropylene glycol, polyglycerol, sorbitan monostearate, sorbitan monooleate, sorbitan monopalmitate, sorbitan monolaurate, sorbitan tristearate, sorbitan trioleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monolaurate, polyoxyethylene fatty acid esters, polyoxyethylene fatty alcohol ethers, polyoxyethylene alkylphenol ethers, polyoxyethylene polyoxypropylene block copolymers, alkylbenzene sulfonates, alkyl sulfonates, alkyl Sulfates, alkyl phosphates, alkyl quaternary ammonium salts, alkyl glycosides, alkyl polysaccharides, alkyl glucosamides, alkyl glycerol ethers, alkyl glycerides, alkyl alcoholamides, alkyl diethanolamides, alkyl isopropanolamides, alkyl dimethylamine oxides, alkyl dimethyl betaine, alkyl dimethyl sulfobetaine, alkyl dimethyl hydroxypropyl sulfobetaine, alkyl dimethyl carboxybetaine, alkyl dimethylamine hydantoin, alkyl dimethylamine propionate, alkyl dimethylamine butyrate, alkyl dimethylamine valerate, alkyl dimethylamine hexanoate, alkyl dimethylamine heptanoate, alkyl dimethylamine octanoate, alkyl dimethylamine nonanoate, alkyl dimethylamine decanoate, alkyl dimethylamine undecanoate, alkyl dimethylamine dodecanoate, alkyl dimethylamine tridecanoate, alkyl di Methylamine tetradecanoate, alkyl dimethylamine pentadecanoate, alkyl dimethylamine hexadecanoate, alkyl dimethylamine heptadecanoate, alkyl dimethylamine octadecanoate, alkyl dimethylamine nonadecanoate, alkyl dimethylamine eicosanoate, alkyl trimethylammonium chloride, alkyl trimethylammonium bromide, alkyl trimethylammonium iodide, alkyl dimethyl benzylammonium chloride, alkyl dimethyl benzylammonium bromide, alkyl dimethyl benzylammonium iodide, alkyl pyridine ammonium chloride, alkyl pyridine ammonium bromide, alkyl pyridine ammonium iodide, alkyl quinoline ammonium chloride, alkyl quinoline ammonium bromide, alkyl quinoline ammonium iodide, alkyl imidazoline ammonium chloride, alkyl imidazoline ammonium bromide, alkyl imidazoline ammonium iodide, alkyl morpholine ammonium chloride, alkyl morpholine ammonium bromide, alkyl morpholine ammonium iodide, alkyl piperidine ammonium chloride, alkyl piperidine ammonium bromideAlkylpiperidine ammonium iodide, alkylpiperazine ammonium chloride, alkylpiperazine ammonium bromide, alkylpiperazine ammonium iodide, alkylhexamethylenetetramine ammonium chloride, alkylhexamethylenetetramine ammonium bromide, alkylhexamethylenetetramine ammonium iodide, alkylethylenediamine ammonium chloride, alkylethylenediamine ammonium bromide, alkylethylenediamine ammonium iodide, alkyldiethylenetriamine ammonium chloride, alkyldiethylenetriamine ammonium bromide, alkyldiethylenetriamine ammonium iodide, alkyltriethylenetetramine ammonium chloride, alkyltriethylenetetramine ammonium bromide, alkyltriethylenetetramine ammonium iodide, alkyltetraethylenepentamine ammonium chloride, alkyltetraethylenepentamine ammonium bromide, alkyltetraethylenepentamine Ammonium iodide, alkylpentaethylenehexamine ammonium chloride, alkylpentaethylenehexamine ammonium bromide, alkylpentaethylenehexamine ammonium iodide, alkylhexamineheptaamine ammonium chloride, alkylhexamineheptaamine ammonium bromide, alkylhexamineheptaamine iodide, alkylheptaethyleneoctamine ammonium chloride, alkylheptaethyleneoctamine ammonium bromide, alkylheptaethyleneoctamine iodide, alkylheptaethylenenonamine ammonium chloride, alkylheptaethylenenonamine bromide, alkylheptaethylenenonamine iodide, alkylnonaminedecaamine ammonium chloride, alkylnonaminedecaamine bromide, alkylnonaminedecaamine iodide, alkyldecaethylenedecaaminedecaamine iodide, alkyldecaethylenedecaaminedecaamine, Alkyl decaethyleneide undecylamine ammonium bromide, alkyl decaethyleneide undecylamine ammonium iodide, alkyl polyoxyethylene ether sulfate, alkyl polyoxyethylene ether sulfonate, alkyl polyoxyethylene ether phosphate, alkyl polyoxyethylene ether carboxylate, alkyl polyoxyethylene ether succinate, alkyl polyoxyethylene ether maleate, alkyl polyoxyethylene ether fumarate, alkyl polyoxyethylene ether tartrate, alkyl polyoxyethylene ether citrate, alkyl polyoxyethylene ether malate, alkyl polyoxyethylene ether lactate, alkyl polyoxyethylene ether glycolate, alkyl polyoxyethylene ether propanolate, alkyl polyoxyethylene ether butanolate, alkyl polyoxyethylene ether pentanol Alkyl polyoxyethylene ether hexyl alcohol, alkyl polyoxyethylene ether heptahydroxyl, alkyl polyoxyethylene ether octahydroxyl, alkyl polyoxyethylene ether nonyl alcohol, alkyl polyoxyethylene ether decyl alcohol, alkyl polyoxyethylene ether undecyl alcohol, alkyl polyoxyethylene ether dodecyl alcohol, alkyl polyoxyethylene ether tridecyl alcohol, alkyl polyoxyethylene ether tetradecyl alcohol, alkyl polyoxyethylene ether pentadecyl alcohol, alkyl polyoxyethylene ether hexadecyl alcohol, alkyl polyoxyethylene ether heptadecanol, alkyl polyoxyethylene ether octadecyl alcohol, alkyl polyoxyethylene ether nonadecanol, and alkyl polyoxyethylene ether eicosyl alcohol.

[0022] Preferably, the auxiliary functional material is selected from any combination of molasses, soybean meal, corn steep liquor, wheat bran, seaweed powder, amino acid powder, humic acid, fulvic acid, chitosan, lignin sulfonate, alkyl glycoside, Tween-80, polyethylene glycol 400, urea, potassium dihydrogen phosphate, magnesium sulfate, ferrous sulfate, yeast powder, sodium lactate, and glycerin.

[0023] The agricultural synergist described in this invention is added to pesticide formulations (insecticides, fungicides, herbicides) or foliar fertilizers at a mass ratio of 0.1 to 5% for the control of tropical crop pests.

[0024] The tropical crops mentioned include, but are not limited to: bananas, lychees, mangoes, longans, sugarcane, citrus fruits, papayas, pineapples, coconuts, rubber trees, coffee, cocoa, etc.

[0025] The pests mentioned include, but are not limited to: thrips, aphids, spider mites, scale insects, whiteflies, leaf miners, leaf rollers, stem borers, stink bugs, leafhoppers, psyllids, etc.

[0026] This invention provides a tea saponin extract, its preparation method, and its application in agricultural synergists. Compared with the prior art, this invention has the following advantages: (1) The present invention uses an ultrafiltration membrane with a specific molecular weight cutoff as a “molecular sieve” to precisely remove “bad molecules” (proteins, macromolecular polysaccharides) that cause the physical stability of pesticide formulations to deteriorate, while retaining “good molecules” such as tea saponins that exert surface activity and “small molecules” that may have synergistic effects.

[0027] (2) Excellent performance and clear synergistic mechanism: The tea saponin extract obtained by this invention has a surface tension ≤40 mN / m. Low surface tension significantly reduces the contact angle between the extract and the leaf surface. Its synergistic mechanism includes: Wetting and spreading: Quickly breaks the surface tension of the liquid, allowing it to spread rapidly into a liquid film on the hydrophobic leaf surface.

[0028] Adhesion and retention: The adhesiveness of natural saponins increases the retention of the pesticide solution on the leaf surface.

[0029] Penetration and absorption: This may be achieved by disrupting the cuticle or regulating stomata, thus promoting the penetration of systemic pesticides. Pot experiments have shown that pesticide retention is increased by 40%, and control efficacy is improved by 25%.

[0030] (3) Green and resource-efficient process: From raw materials (agricultural waste), solvents (ethanol-water) to processes (low-energy membrane separation), the entire process complies with the principles of green chemistry. It realizes the transformation of camellia oil cake from "waste" to "high value-added product", turning waste into treasure.

[0031] (4) Wide compatibility of formulation: Due to the removal of easily mutated macromolecular impurities, this product has good compatibility with most pesticide technicals and formulations, and is not prone to acid-base changes, salting out, flocculation or decomposition, and has a wide range of applications. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments.

[0033] Example 1 A method for preparing a tea saponin extract, comprising the following steps: (1) Pretreatment and defatting: 1 kg of camellia seed cake (main components are tea saponin 18%, crude fat 12%, crude protein 15%, soluble polysaccharide 20%, crude fiber 34%, and the remainder is impurities) produced in the tropical hilly area of ​​Hainan was dried to moisture content <8%, pulverized to 40 mesh, and then Soxhlet extraction or stirring extraction was carried out at 55°C with petroleum ether with a boiling range of 70°C for 2.5 h to remove residual oil. After drying at 50°C with ventilation until no petroleum ether solvent residue was left, 850 g of defatted cake powder was obtained. (2) Ultrasonic-assisted ethanol extraction: 100g of defatted cake powder was mixed with 900mL of 70% ethanol aqueous solution. After ultrasonic extraction (ultrasonic power 450W, ultrasonic power density 0.5W / mL, extraction temperature 60℃, ultrasonic treatment time 25 min), the mixture was centrifuged at 5000 rpm for 10 minutes, filtered and the supernatant was collected. The filter residue was extracted once more, and the two supernatants were combined to obtain the camellia cake extract. (3) Membrane separation purification: a. Microfiltration clarification: The camellia seed cake extract obtained in step (2) is filtered through a ceramic microfiltration membrane with a pore size of 0.1 μm under a pressure of 0.8-1.0 bar to obtain a microfiltration clarified liquid; b. Ultrafiltration to remove impurities: The microfiltration clarified liquid is filtered through a PES ultrafiltration membrane with a molecular weight cutoff of 20 kDa under a pressure of 1.5-2.5 bar to obtain the ultrafiltration permeate; (4) Nanofiltration membrane concentration: The ultrafiltration permeate is dehydrated and concentrated to 1 / 6 of its volume by passing it through a nanofiltration membrane with a molecular weight cutoff of 300 Da under a pressure of 1.0-2.0 MPa to obtain a concentrated solution with a tea saponin content of 60%-80%. (5) Drying and shaping: The concentrated liquid is spray-dried with the inlet air temperature controlled at 170°C and the outlet air temperature controlled at 85°C to obtain 13.2g of the tea saponin extract.

[0034] HPLC (area normalization method) analysis revealed that the tea saponin content was 75.8%, and it also contained 6.5% glucose, 4.2% fructose, 1.4% arabinose and other small molecule sugars, 0.8% gallic acid and 0.5% chlorogenic acid and other organic acids, 0.3% quercetin and 0.2% kaempferol and other flavonoids, as well as 1.1% soluble potassium salts, 0.4% soluble calcium salts, 0.2% soluble magnesium salts and other mineral elements. The protein residue was ≤0.1%, and no macromolecular polysaccharides with a molecular weight >20kDa, crude fiber and lignin were detected. The moisture content was 2.5%, and the surface tension of its 0.1% aqueous solution was 37.2 mN / m.

[0035] Comparative Example 1 A traditional water extraction method for preparing tea saponin extract includes the following steps: Hot water was used instead of the ethanol solution in step (2) for extraction, excluding the membrane separation purification in step (3), and the solution was directly concentrated and dried.

[0036] Results: The obtained product was a dark brown paste with poor solubility, and a precipitate formed after standing in a 0.1% aqueous solution. Testing revealed that the product contained only 32.6% tea saponin, 8.3% moisture, a high protein residue of 6.8%, 21.5% total content of macromolecular polysaccharides (molecular weight >20kDa), starch, and gelatinous substances, 15.7% total soluble sugars, 7.2% flavonoids and polyphenols, 2.9% minerals, and a surface tension of 48.5 mN / m. Furthermore, its addition to pesticides easily led to stratification.

[0037] Comparative Example 2 A method for preparing tea saponin extract by resin refining includes the following steps: Following the ultrafiltration step in Example 1, AB-8 macroporous resin was added for purification. Resin pretreatment: AB-8 macroporous adsorption resin (particle size 0.3-1.25 mm, specific surface area 480-520 m²) was used. 2 / g), soak in 95% ethanol for 24h, stirring 3 times during the period, then wash with distilled water until the effluent has no ethanol odor; then soak in 5% hydrochloric acid solution for 2h, wash with distilled water until neutral, soak in 5% sodium hydroxide solution for 2h, wash with distilled water until neutral, and set aside; sample loading: adjust the pH of the ultrafiltration permeate to 5.0, and pass it through an AB-8 macroporous resin chromatography column (column diameter to column height ratio 1:8, resin packing height 30cm) at a flow rate of 2BV / h (bed volume / hour), with a sample loading volume of 4 times the wet volume of the resin; Elution: After sample loading, first wash with 3 BV distilled water to remove impurities (flow rate 3 BV / h), and discard the washing solution; then use 70% ethanol aqueous solution as eluent, eluent at a flow rate of 2 BV / h, and collect the eluent (collect the eluent fractions with tea saponin content ≥5% by real-time monitoring of the tea saponin peak area by HPLC); De-alcoholization and concentration: remove ethanol from the collected eluent by vacuum distillation at 60℃ and -0.08 MPa to obtain the de-alcoholized solution, and then connect it to the nanofiltration membrane concentration step of Example 1.

[0038] Results: The product had a tea saponin content of 90.5% and a surface tension of 36.8 mN / m. However, the overall cost was approximately 50% higher than that of Example 1.

[0039] Example 2-3 A compound fermentation-type agricultural synergist, the raw material composition (parts by weight) is shown in Table 1: Table 1

[0040] The preparation method of the agricultural synergist includes the following steps: Ingredient Mixing: Mix tea saponin extract with auxiliary materials in a specified ratio, add water to adjust the moisture content to 65%, adjust the pH to 6.0, and inoculate with Bacillus subtilis (commercially available product with an effective viable count of 10 billion / g, inoculation amount 2%), and ferment at 30℃ for 48 hours. After fermentation, dry and pulverize at 50℃ to obtain the agricultural synergist.

[0041] Comparative Example 3 A compound agricultural synergist, with the raw material composition (parts by weight) as in Example 2, is prepared by the following steps: Ingredient mixing: Mix tea saponin extract with auxiliary materials in proportion, add water to adjust the moisture content to 65%, adjust the pH to 6.0, let stand at 30℃ for 48 hours, dry and pulverize at 50℃ to obtain agricultural synergist.

[0042] Example 4 An application of a tea saponin extract, The insecticidal effects of the tea saponin extract prepared in Example 1 and the agricultural synergists prepared in Examples 2 and 3 on tropical crops were tested. Experiment location: A mango plantation in Sanya City, Hainan Province Experimental crop: Mango (variety: Tainong No. 1), peak flowering period Target pest: Mango thrips (Thrips hawaiiensis) Test pesticide: 5% emamectin benzoate (emamectin benzoate) soluble granules, diluted 3000 times. The experimental design is shown in Table 2: Table 2

[0043] The commercial organosilicon synergist listed in Table 2 is Jierun BD-3077 agricultural organosilicon synergist from Hangzhou Baoerde Organosilicon Co., Ltd.

[0044] Application method: Use an electric sprayer to spray evenly, repeating 3 times per treatment, with 30 mango trees per plot. Survey method: Survey the initial insect population before application, and survey the number of live insects 1 day, 3 days, and 7 days after application to calculate the control effect.

[0045] The experimental results are shown in Table 3: Table 3

[0046] Conclusion: The products of Examples 2 and 3 of this invention (compound fermentation type) have significantly better control effects on mango thrips than the unfermented compound tea saponin extract (T3), and are comparable to or slightly better than the commercial organosilicon synergist (T4), with an increase of more than 50% in leaf retention.

[0047] Example 5 An application of a tea saponin extract, The tea saponin extract prepared in Example 1 and the agricultural synergists prepared in Examples 2 and 3 were used to conduct an insecticidal effect test on tropical crops (banana aphids): Experiment location: A banana plantation in Chengmai County, Hainan Province Experimental crop: Banana (variety: Brazilian banana), budding stage Target pest: Banana aphid ( Pentalonia nigronervosa ) Test pesticide: 10% imidacloprid wettable powder, diluted 2000 times. Experimental design: Same as Example 4, except for the addition of a non-fermented physical mixture group (T5: all components in Example 2 except for the fermentation step are simply mixed without fermentation).

[0048] The experimental results are shown in Table 4: Table 4

[0049] The commercial organosilicon synergist listed in Table 4 is Jierun BD-3077 agricultural organosilicon synergist from Hangzhou Baoerde Organosilicon Co., Ltd.

[0050] Conclusion: The fermentation process (T1, T2) improved the efficacy by 15-20 percentage points compared with the unfermented physical mixture (T5), indicating that the fermentation process is crucial to the efficacy enhancement.

[0051] It can be seen that the agricultural synergist prepared by this invention has the following technical effects: (1) Significant synergistic effect: Through the scientific compounding of 10 to 20 kinds of excipients, rich carbon source, nitrogen source and trace elements are provided, which promote the production of active substances such as organic acids, enzymes and small molecule peptides by microbial metabolism, and produce a synergistic effect with tea saponin. The synergistic effect is far better than that of single tea saponin or unfermented physical mixture.

[0052] (2) For tropical crops: In view of the characteristics of thick wax layer on leaves of tropical crops and severe rain erosion, the synergist of this invention significantly improves the ability of the liquid to wet, spread, penetrate and resist rain erosion on the leaf surface.

[0053] (3) Improved insecticidal effect: Pot experiments and field trials have shown that after adding the synergist of this invention, the pesticide residue retention is increased by 40-60%, and the control effect is increased by 25-50%.

[0054] (4) Green and environmentally friendly: The entire process uses biodegradable natural raw materials, which is environmentally friendly.

[0055] (5) Cost advantage: No high-cost purification steps such as macroporous resin are required, and the overall cost is reduced by 30-40% compared with existing high-purity tea saponin synergists.

[0056] Example 6 Application of a tea saponin extract, synergistic effect pot experiment The products obtained in Example 1 and Comparative Examples 1-2 were added at a dosage of 0.5% (w / w) to commercially available high-efficiency cyhalothrin (25g / L EC) (manufacturer: Shandong Henglida Biotechnology Co., Ltd.), and diluted 1500 times with water.

[0057] Using the water group as a blank control group and the solution with 0.5% agricultural organosilicon synergist (specifically, the source-enhancing synergist agricultural organosilicon wetting agent purchased from Hebei Kaihe Biotechnology Co., Ltd.) as a control, aphids on cabbage were sprayed. The results are shown in Table 5.

[0058] Table 5

[0059] The commercial organosilicon synergist listed in Table 5 is Jierun BD-3077 agricultural organosilicon synergist from Hangzhou Baoerde Organosilicon Co., Ltd.

[0060] As shown in Table 5, the control efficacy of the present invention group was 85% and 94% at 1 day and 3 days after application, respectively; the commercial organosilicon group was 88% and 95%; and the blank control group (without synergist) was 65% and 82%. The control efficacy of the present invention is comparable to that of high-end organosilicon, but at a lower cost and more environmentally friendly. Furthermore, leaf residue retention measurements showed that the present invention group had a 45% higher residue retention than the blank control group.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An application of a tea saponin extract, characterized in that, Tea saponin extract is added as an agricultural synergist to the pesticide composition; the pesticide composition includes the active pesticide ingredient and the agricultural synergist; the content of tea saponin extract in the pesticide composition is 0.1wt%-5wt%; the formulation of the pesticide composition is any one of aqueous solution, emulsifiable concentrate, wettable powder, suspension concentrate or water-dispersible granules.

2. The application of the tea saponin extract according to claim 1, characterized in that, The agricultural synergist is prepared by fermentation of the following raw materials using microbial strains in the following weight percentages: Tea saponin extract 30-100%, auxiliary functional materials 0-70% The inoculation amount of the microbial strain is 0.5% to 5% of the total mass of the agricultural synergist.

3. The application of the tea saponin extract according to claim 2, characterized in that, The preparation method of the agricultural synergist includes the following steps: (1) Mix tea saponin extract with auxiliary functional materials in a certain proportion, add water to adjust the water content to 50-80%, and adjust the pH to 5.5-7.0; (2) Introduce the microbial fermentation strain and mix thoroughly; (3) Ferment at 30-37℃ for 24-72 hours; (4) After fermentation, dry and pulverize or directly prepare into liquid form to obtain the agricultural synergist.

4. The application of the tea saponin extract according to claim 2, characterized in that, The microbial strains are selected from one or more of Bacillus subtilis, yeast, lactic acid bacteria, and actinomycetes.

5. The application of the tea saponin extract according to claim 1, characterized in that, The preparation method of the tea saponin extract includes the following steps: (1) Pretreatment and degreasing: The camellia oil cake is dried to a moisture content of <8%, pulverized to 20-40 mesh, extracted with petroleum ether to remove residual oil, and dried to obtain degreased cake powder; (2) Ultrasonic-assisted ethanol extraction: The defatted cake powder is mixed with an ethanol aqueous solution, and after ultrasonic extraction, the supernatant is collected by centrifugation and filtration. The filter residue is extracted once more, and the two supernatants are combined to obtain the camellia cake extract. (3) Membrane separation purification: a. Microfiltration clarification: The camellia seed cake extract obtained in step (2) is filtered using a ceramic microfiltration membrane to obtain a microfiltration clarified liquid; b. Ultrafiltration to remove impurities: The microfiltration clarified liquid is filtered through an ultrafiltration membrane to obtain the ultrafiltration permeate; (4) Nanofiltration membrane concentration: The ultrafiltration permeate is dehydrated and concentrated to 1 / 6-1 / 5 of its volume by passing it through a nanofiltration membrane to obtain a concentrated solution with a tea saponin content of 60%-80%. (5) Drying and shaping: The concentrated liquid is spray dried, with the inlet air temperature controlled at 160-180℃ and the outlet air temperature controlled at 80-90℃ to obtain the tea saponin extract.

6. The application of the tea saponin extract according to claim 5, characterized in that, The boiling range of the petroleum ether in step (1) is 60-90℃, the extraction is Soxhlet extraction or stirring extraction, the extraction temperature is 50-60℃, and the extraction time is 2-3h; The drying temperature is 50-55℃, and the drying method is ventilation drying, until no petroleum ether solvent residue remains.

7. The application of the tea saponin extract according to claim 5, characterized in that, In step (2), the volume fraction of ethanol in the aqueous ethanol solution is 60%-75%; the ratio of defatted cake powder to aqueous ethanol solution is 1g:8-10mL. The ultrasonic power density is 0.3-0.5 W / mL, the extraction temperature is 50-65℃, and the ultrasonic treatment time is 20-30 min; The centrifugation speed is 4000-5000 rpm, and the time is 10-15 min.

8. The application of the tea saponin extract according to claim 5, characterized in that, The pressure of the ceramic microfiltration membrane in step (3) is 0.8-1.0 bar, and the pore size of the ceramic microfiltration membrane is 0.1-0.5 μm; The ultrafiltration membrane is filtered at a pressure of 1.5-2.5 bar, and the ultrafiltration membrane is a spiral-wound polysulfone (PS) or polyethersulfone (PES) ultrafiltration membrane with a molecular weight cutoff of 10kDa-30kDa.

9. The application of the tea saponin extract according to claim 5, characterized in that, The nanofiltration membrane concentration pressure in step (4) is 1.0-2.0 MPa, and the molecular weight cutoff of the nanofiltration membrane is 200-500 Da.

10. The application of the tea saponin extract according to claim 5, characterized in that, The tea saponin extract contains 60%-80% tea saponin; the static surface tension of a 0.1 w / v% aqueous solution of the tea saponin extract at 25°C is ≤40 mN / m.

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